You need to pull out the rubber/plastic thing, then you can get straight into the forward bolt from below. The rearward bolt can be accessed with a crescent wrench from underneath the truck. No need to remove the bumper.
DO BE SURE that you account for the nuts inside the square channel/frame...
Your AC doesn't run for 4-5 hours straight, the FAN may run for that long, but the compressor does not. It could have easily started and caused the trip. Soft start device would be beneficial for numerous reasons, and the first thing I would try with this.
Source: I have a Caravel 22 on this...